Between Necessity and Hubris

As the planet crosses climate tipping points, geoengineering — once taboo — re-emerges as science’s boldest, riskiest bid to cool a fevered Earth

- SHISHIR PRIYADARSHI & SANDRA KURIAN

Geoengineering is not only about science but about sovereignty

The world is hurtling toward climate tipping points faster than mitigation can catch up. Melting ice sheets, a faltering Atlantic circulation, and parched lands are no longer scenarios for 2100—they are the living reality of this decade. And as global emissions continue their stubborn climb, a once-taboo set of options is creeping into mainstream 'Geoengineering.

Geoengineering, in this context, refers to large-scale technological interventions designed to deliberately alter the Earth’s climate system as a way to counteract global warming. It spans two main approaches: Carbon Dioxide Removal (CDR), which seeks to pull existing greenhouse gases out of the atmosphere and lock them away in soils, oceans, or rocks; and Solar Radiation Management (SRM), which aims to reflect a fraction of the sun's rays back into space to temporarily cool the planet. Both are seen as potential complements—not substitutes—to cutting emissions, but they come with scientific uncertainties, ecological risks, and profound geopolitical implications.

Carbon Removal: Beyond Planting Trees

CDR is not just about forests and tree cover. Scientists divide the field into at least three categories:

▸Land-based methods like biochar, which heat crop residue into a stable soil additive that locks carbon for centuries while improving fertility.

▸ Geochemical methods like enhanced rock weathering, where ground minerals react with CO2 and improve soil nutrients or ocean alkalinity.

▸ Ocean-based strategies, such as large-scale seaweed farming, are theoretically capable of vaulting atmospheric carbon deep into ocean sediments.